Questions regarding efficient storing and representing data within a software application.

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2answers
97 views

Data structure to hold Excel column names with their values

I am learning how to read Excel workbooks in Java and want to know what a good Data Structure will be for holding Column names with the values under them. Example: I want to be able to call a ...
2
votes
2answers
191 views

Do any languages other than Haskell implement strings as linked lists of characters?

Haskell’s String type is an alias for [Char] (i.e. a linked list of Chars). Does any other language use an implementation of strings like this?
0
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0answers
16 views

Randomly sampling chunks of a tree

I have a (non-binary) tree from which I want to sample various leaf and non-leaf nodes semi-randomly. The tree is generally less than 50 leaf nodes in all. The criteria for sampling is somewhat fuzzy ...
7
votes
2answers
157 views

Data structure for two-dimensional board games in Functional languages

I am creating a simple MiniMax implementation in the functional programming language Elixir. Because there are many perfect-knowledge games (tic tac toe, connect-four, checkers, chess, etc), this ...
3
votes
1answer
164 views

Potential legal issues with lock-free / wait-free structures / algorithms

While researching the subject matter - lock-free and wait-free data structures - I'm seeing a worrying amount of mention of patents with this area. I've hobby-researched compression algorithms years ...
0
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0answers
39 views

Algorithm: Calculate average time in given time frame

I have a complex problem to solve. Problem Statement: I have a list of cities: Lets say New York, LA Las Vegas California The list of cities is limited, not more than 10. Now there are peoples ...
2
votes
1answer
50 views

Data structure to store breakable parts of a mesh

I have a wall mesh that is divided into destructible pieces. As it gets destroyed, the wall can collapse into separate objects with physics that can be destroyed as well. (Cut the wall in half ...
6
votes
2answers
89 views

Casting a nullary data constructor between types

Suppose I have a parametrized data type with more than one nullary (constant) data constructor, such as: data Check a = Valid | Invalid | Unsure a Sometimes I want to manipulate the non-constant ...
4
votes
5answers
197 views

How to store math expression in c++ list

I am parsing a infix math expression to a postfix form. I want to store it in a list like [4.5, 3, 0.25, +, -] so that I can process it once it's parsed. I could store it in a string again, but I ...
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votes
1answer
90 views

How do I implement autocomplete functionality for a big website? [closed]

I am looking to implement a custom autocomplete functionality for a travel website with huge amounts of data. I am thinking of implementing it using a trie. But how do I handle it if the data cannot ...
0
votes
1answer
56 views

Complex Math Formula: Predict the value of variable if result is known

I have a very complex math formula/equation which involves exponential. Formula: X + 2 = Y *PS: The above is just an example to illustrate my problem. The real formula is way more complex than this....
2
votes
3answers
181 views

Why are arrays often treated as second-class citizens?

In many programming languages, arrays don't get as much attention as other data structures. In Java, there is no Array<T> type collection to make arrays feel more consistent, such as in ...
0
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0answers
11 views

How to segregate data between user groups in Django?

django.contrib.auth has User and Group models. I'm using the User model for my users, and the Group model to manage their broad permissions (access to admin site, access logs, etc). I also have my ...
0
votes
1answer
105 views

Should smaller data types be used in intermediate code?

I often use smaller data types in structs/classes when it is needed in memory savings. I also use them in network/disk IO. My question is if intermediate code that use those objects with smaller data ...
2
votes
2answers
33 views

Composition of Data Transfer Objects

Let's say I want to create a shop/order system. I'll have an Order DTO to which I'll map the data from a request and results from the database. The object will consist of an order number, a customer ...
12
votes
4answers
3k views

Can a C struct behave like it had a function?

I use C and structs where a struct can have members but not functions. Assume for simplicity that I want to create a struct for strings that I name str and I want to be able to do str.replace(int i, ...
1
vote
1answer
58 views

Data Storage Architecture: Storing Hierarchical Data (JSON/BSON)

Say you have the hierarchical storage concept of "Foo." "Foo" holds an id, various values, and zero to many "Foo." Obviously, in turn, the child elements can hold zero to many Foos. The data is purely ...
0
votes
1answer
87 views

What data structure to use to save the address of edges in depth first search?

I am currently trying to write my own Depth First Search. I have created a class called node. class node{ private: bool is_visited; <data structure to collect edges> ...
1
vote
1answer
105 views

Understanding recursive solution of some algorithm

Most of the time we need to understand someone else' code for example I am studying Graph Algorithms from Sedgewick's online resources, the particular code example is taken from cycle detection ...
1
vote
1answer
50 views

Generate a string generator (constant associative array)

There is a finite set of unique strings and a limited key space. One key corresponds to one string value and a function must exist to perform the resolution. There is no need to support other ...
2
votes
1answer
137 views

Choice of variable names and types in graph algorithm

I am learning algorithms and data structures from this awesome resource Algorithms. Rather than doing dry reading I am trying to re-write all the code myself so that I can learn coding as well as ...
1
vote
1answer
48 views

Best structuring for IRC message decoding (Python)

I am writing a simple IRC chatbot in Python and, in an effort to get more into OOP, made a basic "connection" class that manages all the backing-and-forthing involved. But IRC protocol is rather ...
2
votes
2answers
137 views

C#/VB struct – how to avoid case with zero default values, which is considered invalid for given structure?

How to implement some constrained .NET struct/structure (let's say LimitedString), where its state with default values (set by CLR to technical defaults, i.e. nulls, zeros, etc.) should be prohibited ...
-1
votes
1answer
150 views

What is the faster way to save and browse objects using vectors +/or maps? (c++)

I'm doing a object Garbage class using c++: #include "Object.h" class ObjectGarbage { public: ObjectGarbage(); ~ObjectGarbage(); void Call_All_Objects() { //(...
1
vote
1answer
24 views

How do you achieve the 'BST Property' in a Template Binary Search Tree?

We recently started learning about binary search trees. We created one of our own using integers as our Key/Data. It's easy to achieve the BST property using an int key, but what happens when we ...
0
votes
1answer
62 views

Alert when size of continuous stream of events exceeds 1000

A friend of mine was recently asked this question in an interview. Lets say there is a continuous stream of incoming events E1, E2 each with timestamp of entry associated with them. Write a java ...
4
votes
1answer
55 views

Efficient Value-Lookup in List of k-Tuples

I've encountered a problem in a personal project that I think could be solved by a particular data structure but I'm not sure what. The problem is as follows: Given a set of k-tuples, provide an ...
2
votes
2answers
89 views

Best practices for getting data by different criteria

I have one BL function and one SQL stored procedure (let's name it: getPersonDetailsById) which returns person details by passing his PersonId. Now I need to get the same details (data table) but by ...
0
votes
1answer
92 views

How can I avoid duplicating information in this scenario?

I have a Data class that can be placed inside a DataCollection class that can be placed inside a DataCollectionCollection class. Kinda like an egg can placed inside a box that can be placed inside a ...
2
votes
0answers
41 views

Cache-conscious data structure that does not require hashing

I am looking for a cache conscious data structure that does not require hashing. This is to avoid HashDoS without needing to use cryptographic PRFs such as SipHash, which are slow (~1 cycle/byte) &...
4
votes
2answers
97 views

Database design, processor vs inconsistency

I was wondering, if I have a table that stores, lets say, a user's transactions, then when I need to fetch the user's current balance I would have to go and use SUM() like SELECT SUM(value) FROM ...
1
vote
1answer
116 views

Does algorithm time complexity O(5) considered as O(1)? [duplicate]

I have someone homework to make and in the instructions it says that we need to implement a function in O(1). Now, does it mean that I can make my function in O(5) or O(2) or whatever?
3
votes
1answer
225 views

How to pass data to OOP objects?

I'm new to this whole thing, so please tell me if I'm doing this wrong of if there's a better spot for my question. I'm making a game with basic systems for projectiles, npcs and items. This game ...
0
votes
2answers
86 views

JSON or XML or other - most time efficient for largely “read” of structured data

Considering that using a relational DB or other hierarchical or such databases is not an option, looking for the alternative approach using a simple (but very fast, efficient, distributed KV-store). ...
7
votes
2answers
150 views

How to best design a job queue with constraints?

Consider the following situation: You have a program which creates numerous 'jobs' that need to be processed and places them into a queue. You have other worker programs which grab the next 'job' in ...
4
votes
1answer
137 views

Word ladder efficency problem

I have a problem dealing with word ladders. The problem is: given two words and a dictionary file, find the shortest word ladder between the two words. So if given the words cat and pot: cat -> ...
4
votes
0answers
76 views

Modelling a complex schedule of work

I've got a real-world problem that I'm trying to represent and automate. I've simplified and abstracted it down to the following: There are n places of work (P1, P2, ..., Pn). Each place, Pn has a ...
4
votes
2answers
161 views

How to design an iterable but immutable (read-only) collection

My program models a sport tournament which has one or many events or categories. The class Event has members like players or courts as a List, as well as some dictionaries using the class Map. So far ...
2
votes
2answers
211 views

Is it a bad practice to use JSON strings as keys of objects?

On languages such as Haskell, most datatypes have instances which allow their values to be used as keys of structures such as Maps. JavaScript has reasonably fast maps, there called objects, but those ...
2
votes
1answer
70 views

Caching in '3D' - data-structures and octree recursion - hrrm!

The Situation: I have 68GB of data that is conceptually realized as a 3D matrix of 8-bit values with dimension 4096*4096*4096. I need to access multiple sections of this data for processing in a ...
1
vote
1answer
67 views

Joining binary trees

Suppose we have a set of binary trees with their inorder and preorder traversals given and where no tree is a subtree of another tree in the given set. Now another binary tree Q is given. Find ...
1
vote
2answers
246 views

What is the best data structure to store 2 keys and 3 values?

Well, I am having two keys and 3 values for that. Say key1,key2,value1,value2,value3. In future may the values can be increased like value4, value5 so on. I need to get the values(value1,value2,...
0
votes
1answer
67 views

Datagrids vs Databases - what are the differences?

There are some datagrids I had quick look into: Angular UI Grid ag-Grid, one more link Kendo UI Grid Also, previously I had a very small experience with MySQL. What are the differences between (a)...
2
votes
2answers
74 views

Algorithm for implementing QOS in my proxy

Here's the situation: I'm making a proxy (for the moment running on my laptop) which deals with HTTP(S) requests from incoming clients (for the moment only one client, i.e. my Chrome browser on my ...
0
votes
1answer
22 views

What relationship describes two different abstractions of the same dataset

I am wondering if there is a specific term for when multiple representations are data equivalent. Meaning that you can transfer the data from one representation to the other without any loss of data. ...
-1
votes
1answer
73 views

Data structure for storing sorted data

What's a good way to store loads of sorted string on a file so that inserts and reads are fast? I could store it up in a tree, and read/modify/store it as needed, but that seems wasteful for ...
2
votes
1answer
67 views

Matrix multiplication range queries

I have a huge list of matrix i.e A = {M0, M1, M2 .. Mn}. I have a task to find the product of all the matrices in a given range {x,y} i.e Mx * Mx+1 * Mx+2 ... * My. I would like to know if there is ...
1
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2answers
122 views

What design patterns exist for large dataset manipulation within MVC for a rich client data grid?

I want to feed an HTML5 data grid with large data sets that the client will want to manipulate in different ways, e.g. aggregation, grouping, pivoting. The data comes from different web services and ...
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votes
4answers
67 views

How can I represent a multi-dimensional grid? [closed]

I'm trying to find an efficient way to represent a grid in any number of dimensions. I would want to be able to specify a set of coordinates and then get the value stored in the location on the grid. ...